Electrically-heated steam boiler



Aug. 18, 1925.

J. HEINRICH ELECTRICALLY HEATED STEAM BOILER Filed Oct. 2'?", 1922Inventor:

Johann Heinr'i ch a Ma His Attorne Patented Aug 18, 1925.

UNITED STATES PATENT ()FFICE.

JOHANN HEINRICH, 0F BERLIN, GERMANY, ASSIGNOR TO GENERAL ELECTRIC ICOMPANY, -A CORPORATION OF NEW YORK.

ELECTRICALLY-HEATED STEAM BOILER.

Application filed October 27, 1922. Serial No. 597,266.

T 0 all whom it may concern:

Be it known that I, J OHANN HEINRICH, a citizen of th German Republic,residing at Berlin, Pankow, Kreuzstrasse 18, Germany, have inventedcertain new and useful Improvements in Electrically-Heated SteamBoilers, of which the following is a specification.

The present invention relates to steam boilers in which a current ofelectricity flowing from one electrode to another is caused to give upheat energy to the fluid in which they are immersed. As commonlyconstructed the electrodes are surrounded by relatively long insulatingtubes through whichthe fluid to be heated flows. The regulation of theoutput of such boilers is obtained by changing the resistance of thefluid column through which the current flows. To accomplish this thetubes and electrodes are moved axially one with respect to the other.When the boiler is operated on high potential circuits these tubes haveto be very long and their manufacture is extremely difficult andcomplicated. These long tubes are also objectionable because the boilershell has to be correspondingly long tocontain them, and thus for agiven output the boiler as a whole becomes unduly large.

The present invention has for its object to improve boilers of theelectrode type described, and this is accomplished by so constructingand arranging the parts that the resistance of the fluid column ischanged by relative rotary motion of the insulating body or tube andelectrode as distinguished from axial movement thereof. By reason ofthis arrangement the tubes can be made relatively short and hence easyto manufacture and the boiler shell for a given output materiallyshortened.

For a consideration of what I believe to be novel and my invention,attention is directedto the accompanying description and the claimsappended thereto.

In the accompanying drawing which illustrates certain of the embodimentsof my invention, Fig. 1 is a vertical section of one of my improvedboilers; Fig. 2 is a cross section of the same; Fig. 3 is a verticalsection of a modified construction; Fig. 4 is a cross section of thesame; Fig. 5 is a vertical section of a further modification; Fig. 6 iscross section oi the same; Fig. 7 is a vertical section of a furthermodification and Fig. 8- is a cross section of the same.

Referringfirst to Figs. 1 and 2, the boiler shell comprises acylindrical portion 10 and upper and lower heads .11 and, 12. Theseparts may be of any suitable metal and preferably follow standard boilerconstruction as to strength, union of parts,- etc. Located within theshell is a relatively short, vertically-disposed body or tube 13 made ofgood insulating material which will stand up under the eflects oi heatand hot fluid, in this case water. To the upperend of the tube issecured a bridge piece 14, and the latter is suspended from the lowerend of a spindle 15 that extends upwardly through the head 11. Thisspindle is packed pressure-tight where it passes through the head but asthis is unessential to an understanding of the invention, the details ofthe packing are omitted. The electrodes, of which there are four in thiscase, are arranged in pairs, 16 and 17 forming one pair and 18 and 19forming the other pair, and current flows from one electrode of a pairto the other of said pair. have the same, or substantially the same,potential are located within the insulating tube and the others outside.Due to this arrangement all tendency for the current of electricity toflow across the tube is prevented. The electrodes are all stationary andare suspended by rods 20 which also form conductors to carry current toand from them. These rods Where they pass through the head should bewell insulated, but as the insulators form no part of the presentinvention the details are omitted. The electrodes have considerablelength and width so as, to provide suitable cross-sectional area for thedissipation of heat, and when viewed in plan form segments of circles,the axes of which coincide with that of the insulating body of tube 18.The tube 13 is provided with suitable slots or openings 21 in its wallthrough which fluid is free to flow, there being two slots or openingsin the present illustration, and said tube is supported a short distanceabove the bottom wall of the shell so as to permit free access of thefluid to the inside thereof.

The practical effect of the slots 21 is to divide the insulating tubeinto two parts but for mechanical reasons it is preferable to unite theparts of the tube either above or The electrodes which should bemaintained at a level sufiicient to cover the electrodes.

As the parts now stand the resistance of the current carrying fluidcolumn is at the maximum and hence the heating effect of the current isat the minimum. By rotating the insulating tube 13 through the bridge14. and spindle 15 as for example by the worm wheel and worm 22, theresistance of said column is decreased. This is due to the fact thatsuch turning movement "moves the openings 20 in the tube closer to oneside of the electrodes than the other and hence the length of the fluidcolumns through which the current must flow in passing from oneelectrode in each pair to the other is decreased. As the amount of theresistance decreasesthe heating effect is increased because of thegreater flow of current.

In the modification illustrated in Figs. 3 and 4, the electrodes arecircular, 25 indieating thecentral stationary electrode and 26the outer.Between the electrodes is a body of insulating material comprising'twoconcentric insulating tubes 27- and 28, each of which is provided withslots or openings through which the fluid columns flow, Asshown eachtube has two slots or openings 29 which extend lengthwise andare-angularly displaced by 180. It will be noted from Fig. 4 that theslots or openings in one tube are an ularly displaced from those in theother tu e by 90. The effect of this is to cause the fluid to flow in asort of zigzag path and hence the resistance to flow of current can bemade greater than with the more simple construction shown in Figs. 1 and2. Each tube is supported bya bridge piece 14 as before, only portionsof which are shown, and through said pieces the tubes'can be ro-. tatedrelatively to each other and hence the resistance of the fluid columnmay be varied. The electrodes are supported in a manner similar to thatillustrated in Fig. 1.

In the modification shown in Figs. 5 and 6 a body of insulationcomprising disks or members 30 and 31 are arranged between the lowerstationary electrode 32 and the upper electrode 33. Each of said disksis slotted orcut away to provide three hollow arms 34 with fluidpassages 34 between them, and said bodies are carried by suitablesupports 35 and 36, one or both of which are adjustable. As shown thearms on the upper body are directly over the passages on the lower bodyso that the fluid follows a zigzag path. .By rotating one disk withrespect to the other from the position indicated the resistance of thecolumn of fluid can be decreased and the current flow increased. Careshould be exercised to see that the resistance of the fluid column fromone electrode to another and around the disks is made greater than thatof the column through the disks. This can readily be accomplished bymaking the disks substantially larger in diameter than the electrodes.

. In Figs. 7 and 8 is shown a modification of the structure shown inFigs. 5 and 6 in which disks 37 and 38 are'employed, each of which isprovided with a number of holes, perforations of fluid-carrying passages39, there being, three such passages shown.- Relative rotation of thediskwill cause the resistance ofthe fluid column to be varied, and hencethe output of the boiler.

In accordance with the provisions of the patent statutes, 1- havedescribed the principle of operation'ofmy invention, together withapparatus which I now consider to represent the best embodimentsthereof, but I desire to have it understood that the apparatus shown isonly illustrative-and that the invention may be carried out by othermeans.

What I claim as new and desire-to secure by Letters Patent of the UnitedStates, is:

1. In an electrically heated boiler, the combination of afluid-containing shell, electrodes, a body ofinsulatingmaterial which issituated between the electrodes and defines the length of the pathbetween the electrodes, and means for moving said insulating body tovary the length of the path between said electrodes. 7

2. In an electrically heated boiler, the combination of afluid-containing shell, a pair of electrodes, a perforated body ofinsulating material whichis situated between said electrodes and definesthe length of the path between the, electrodes, and means for moving thebody to vary the length of the v path between said electrodes. 7

3. In an electrically heated boiler, the combination of a pair ofelectrodes, a perforated body of insulation which 'is situated betweenthe electrodes and defines the length of the path between them, theelectrodes and body having a common axis, a fluidcontaining shell 'whichencloses the electrodes and body, and means external to the shell forrotating said body for changing the length of the path between theelectrodes. V v

4. In an electrically heated boiler, the combination of a pair ofelectrodes, a perforated body of insulation which is situated betweenthe electrodes and has the same axis, an enclosing shell which containssaid electrodes,'body and fluid to be vaporized, and means for movingthe said body between the electrodes to vary thelength of the fluidpath'between the electrodes.

5. In an electrically heated boiler, the combination of afluid-containing shell, a

pair of electrodes which are supported within the shell from one of itswalls, a tubular body of insulating material which 'issituate betweenthe electrodes and'is mounted to turn, said body having one or moreslots through which fluid asses, and means for turning said body wit outmoving it axially to change the position of the slot to vary the lengthof the fluid path between the electrodes.

6. In an electrically heated boiler, the combination of afluid-containing shell, an inlet for liquid, an outlet for vapor, a pairof electrodes arranged side by side within the shell, a body ofinsulating material which is of cylindrical shape in cross-section andwhich extends between the electrodes, and a spindle for supporting andturning said body between the electrodes so. as to cilliange the lengthof the fluid path between t em.

7. In an electrically heated boiler, the combination of,a-fiuid-containing shell .having an inlet for fluid and an outlet forsteam. a cylindrical body of insulating material which is mounted withinthe shell for angular adjustment and electrodes also mounted within theshell and arranged in pairs, one member of each pair being locatedwithin said body and-the other outside, the electrodes located withinthe body being subjected tosubstantially the same potential.

.8. In an electrically heated boiler, the combination of afluid-containing shell having an inlet for fluid and an outlet forsteam, a cylindrical body of insulating material tential, and means forsupporting the electrodes within the shell.

9. An electric heater comprising a plurality of hollow insulatingmembers of difi'erent sizes disposed in substantial coaxial relation,one within the other, each member having an opening in its sidewall, andone or more of said members being rotatable relatively to the othermember or members, whereby the angular relation of the variousslits maybe varied, an electrode mounted within the inner hollow member and anelectrode surrounding the outer hollow member.

,10. An electric heater comprising a series of hollow insulating membersof increasing sizes, disposed in substantial coaxial relation one withinthe other, each of said members having a vertically disposed slit in itsside wall and one or more of said members being independently rotatable,whereby the angular relations of the slits may be varied,

an electrode within the' inner member and an electrode surrounding theouter member and spaced therefrom.

In witness whereof, I have hereunto set my hand this thirtieth day ofSeptember,

JOI-IANN HEINRICH.

